Conventionally, in the field of image forming apparatuses such as laser printers, a configuration has been proposed in which the positions of a plurality of developing apparatuses are changed between a withdrawn position and a developing position. For example, according to the technology disclosed in Japanese Laid Open Patent No. 2004-20855, the positions of a plurality of developing apparatuses can be changed on the basis of the driving force of a single drive motor. In addition, the number of developing apparatuses that are driven by a single position changing operation can be decreased by staggering the timing for changing the positions of at least one of the developing apparatuses with respect to the timing for changing the positions of other developing apparatuses. According to this technology, developing apparatuses can be smoothly driven even with a low torque drive motor.